30 Apr How to Make Your Home Office Video Conference Sound Its Best
Even before the pandemic, more and more people were working from home regularly. Thanks to contemporary computers and cellphones, with better displays, high-definition audio, and integration between mobile apps and office-based software, video conferencing is easier now than it ever has been.
However, the quality of video conferencing depends on more than just technology. Factors such as poor sound clarity, room and system effects, and intrusive extraneous noise, can limit speech intelligibility, which is our ability to understand dialogue, and reduce the overall effectiveness of a video conference.
At BKL, we often provide acoustical design recommendations to improve speech intelligibility in meeting rooms and video conference spaces, so we thought we’d share some tips for those of us now working from home.
Traditional analogue telephone connections limit the audio to a narrow range of frequencies that are most important to speech intelligibility. Over the phone, voices are easy to understand, yet don’t sound as natural as they would in person.
Contemporary 4G (and 5G) cell phones and voice over Internet Protocol (VoIP) systems balance audio quality with data usage. When the data network has bandwidth capacity, the sound and video quality can be high. If the network is limited, the signal can be low. This results in robotic voices or pixelated video.
Therefore, to have high-quality sound and video, you need a high-speed network internet connection.
Room and VoIP System Effects
Speech intelligibility is strongly linked to the signal-to-noise ratio. For a spoken message to be easily comprehended, the signal (i.e., a person’s voice) must be louder than the background noise. This can be particularly important in cell phone or VoIP systems, where the non-audible triggers may be less obvious.
Noise, in this context, can mean many different things:
- Background noise in the source room that is picked up by the microphones, including traffic noise, mechanical heating or cooling systems, rustling papers, noisy children, etc.
- Reverberation (or reflected sound) in the source room that is picked up by the microphones and passed through the audio system.
- Background noise in the receiving room, which can obscure or mask the sound coming from the loudspeakers.
- Reverberation in the receiving room, which can muddy the sound from the loudspeakers and reduce speech intelligibility.
- System-generated noise within the VoIP or audio equipment.
Signal-to-noise ratio is also affected by the distance between the microphone and the person talking. In most cases, the background noise in any room is pretty consistent throughout the space. The signal level, on the other hand, falls off significantly as the distance from the person’s mouth to the microphone increases.
Consequently, the three main requirements for good acoustics during video conferencing are:
- Low background noise
- Low reverberation
- Microphones located close to the talkers
If everyone on the call can apply these suggestions, you’ll enjoy a higher quality, more natural sounding video conference.
The Right Room Makes A Difference
When choosing a room for your video conference, avoid one that’s affected by road traffic noise or noise from the adjoining streets or businesses. Also, avoid rooms that have noisy HVAC systems, such as AC units or ventilation fans that may be audible to others. Background noise can also affect the way you speak or how the microphone processes your voice.
Many webcam microphones use simple noise-cancelling or signal-compression systems to provide a flat audio response. But when the background noise varies or is unduly loud, these response systems can drop the signal or muffle the sound as the compression kicks in.
Try to select a room with a lot of soft furnishings, such as a couch or heavy drapes. Soft, sound-absorbing materials control reverberation and help speech sound more natural.
Avoid rooms with hard surfaces—like glass, drywall, or concrete. These surfaces reflect sounds, making the room sound louder, and speech seem harsh or muddy.
Many video conference participants use the microphone on their webcams. Unfortunately, even in expensive webcams with high-quality video, the integral microphones aren’t very sophisticated, and often rely on simple microphone response technology. This can result in poor or muffled audio response, audio feedback, or slap-back echo effects.
Where practicable, use a dedicated table-top microphone or high-quality headset.
To maximize the signal-to-noise ratio and minimize the potential to pick up disrupting background sounds, position yourself as close to the microphone as possible.
Happy Video Conferencing!
We hope this helps make your video conferences more efficient and less frustrating!
By following these simple recommendations, it is possible for everyone to improve the audio quality of their video-conferencing so speech intelligibility is good for all.
Take care and stay safe during these times from everyone at BKL Consultants Ltd.